Association Between VEGF Expression and Diffusion Weighted Imaging in Several Tumors—A Systematic Review and Meta-Analysis

To date, only a few studies have investigated relationships between Diffusion-weighted imaging (DWI) and Vascular endothelial growth factor (VEGF) expression in tumors. The reported results are contradictory. The aim of the present analysis was to review the published results and to perform a meta-analysis regarding associations between apparent diffusion coefficients (ADC) derived from DWI and VEGF expression. MEDLINE library was screened for relationships between ADC and VEGF expression up to January 2019. Overall, 14 studies with 578 patients were identified. In 10 studies (71.4%) 3 T scanners were used and in four studies (28.6%) 1.5 T scanners. Furthermore, seven studies (50%) had a prospective design and seven studies (50%) had a retrospective design. Most frequently, prostate cancer, followed by rectal cancer, cervical cancer and esophageal cancer were identified. The pooled correlation coeffcient of all tumors was r = 0.02 [95% CI 0.26–0.21]. ADC values derived from routinely acquired DWI do not correlate with VEGF expression in various tumors. Therefore, DWI is not sensitive enough to reflect angiogenesis-related microstructure of tumors

Apparent Diffusion Coefficient for Distinguishing Between Malignant and Benign Lesions in the Head and Neck Region: A Systematic Review and Meta-Analysis

Background: The purpose of the present meta-analysis was to provide evident data about use of apparent diffusion coefficient (ADC) values for distinguishing malignant and benign lesions in the head and neck region. Material and Methods: MEDLINE and Scopus databases were screened for associations between ADC and malignancy/benignancy of head and neck lesions up to December 2018. Overall, 22 studies met the inclusion criteria. The following data were extracted: authors, year of publication, study design, number of patients/lesions, lesion type, mean value, and standard deviation of ADC. The primary endpoint of the systematic review was the analysis of the association between lesion nature and ADC values. The methodological quality of the involved studies was checked according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) instrument. The meta-analysis was undertaken by using RevMan 5.3 software. DerSimonian and Laird random-effects models with inverse-variance weights were used without further correction to account for the heterogeneity between the studies. Mean ADC values including 95% confidence intervals were calculated separately for benign and malignant lesions. Results: The acquired 22 studies comprised 1,227 lesions. Different malignant lesions were diagnosed in 818 cases (66.7%) and benign lesions in 409 cases (33.3%). The mean ADC value of the malignant lesions was 1.04 × 10−3 mm2 /s, and the mean value of the benign lesions was 1.46 × 10−3 mm2 /s. Lymphomas and sarcomas showed the lowest calculated mean ADC values, 0.7 and 0.79 × 10−3 mm2 /s, respectively. Adenoid cystic carcinomas had the highest ADC values (1.5 × 10−3 mm2 /s). None of the analyzed malignant tumors had mean ADC values above 1.75 × 10−3 mm2 /s. Conclusion: ADC values play a limited role in distinguishing between malignant and benign lesions in the head and neck region. It may be only suggested that lesions with mean ADC values above 1.75 × 10−3 mm2 /s are probably benign. Further large studies are needed for the analysis of the role of diffusion-weighted imaging (DWI)/ADC in the discrimination of benign and malignant lesions in the head and neck region

Opening the Black Box: Finding Osgood’s Semantic Factors in Word2vec Space

State-of-the-art models of artificial intelligence are developed in the black-box paradigm, in which sensitive information is limited to input-output interfaces, while internal representations are not interpretable. The resulting algorithms lack explainability and transparency, requested for responsible application. This paper addresses the problem by a method for finding Osgood’s dimensions of affective meaning in multidimensional space of a pre-trained word2vec model of natural language. Three affective dimensions are found based on eight semantic prototypes, composed of individual words. Evaluation axis is found in 300-dimensional word2vec space as a difference between positive and negative prototypes. Potency and activity axes are defined from six process-semantic prototypes (perception, analysis, planning, action, progress, and evaluation), representing phases of a generalized circular process in that plane. All dimensions are found in simple analytical form, not requiring additional training. Dimensions are nearly orthogonal, as expected for independent semantic factors. Osgood’s semantics of any word2vec object is then retrieved by a simple projection of the corresponding vector to the identified dimensions. The developed approach opens the possibility for interpreting the inside of black box-type algorithms in natural affective-semantic categories, and provides insights into foundational principles of distributive vector models of natural language. In the reverse direction, the established mapping opens machine-learning models as rich sources of data for cognitive-behavioral research and technology

Diversity of felodipine solvates: Structure and physicochemical properties

Solvates of the calcium-channel blocking agent felodipine with three structurally related common organic solvents, acetone (ATN), dimethyl sulfoxide (DMSO) and acetophenone (APN), are described. A relationship between the felodipine packing arrangement in all known solvates and the van der Waals volume of the solvent molecule is established. Intermolecular interaction energies in the crystals are examined using the PIXEL approach in order to rationalize the difference between alternative molecule packing arrangements. DSC studies show that the desolvation onset temperatures of the solvates are closely comparable, despite the large difference in the boiling points of the solvent molecules. The enthalpies of formation derived from the calorimetric data for the solvates are also found to be similar, despite the difference in the van der Waals volume of the solvent molecules.This work was supported by a grant from the President of the Russian Federation no. МК- 67.2014.3 and Russian Foundation for Basic Research (project № 14-03-31001).This is the accepted manuscript. The final version is available at http://pubs.rsc.org/en/Content/ArticleLanding/2015/CE/C5CE00350D#!divAbstract

Pulmonary Vessel Obstruction Does Not Correlate with Severity of Pulmonary Embolism

The aim of the present study was to analyze possible relationships between pulmonary vessel obstruction and clinically relevant parameters and scores in patients with pulmonary embolism (PE). Overall, 246 patients (48.8% women and 51.2% men) with a mean age of 64.0 17.1 years were involved in the retrospective study. The following clinical scores were calculated in the patients: Wells score, Geneva score, and pulmonary embolism severity index (PESI) score. Levels of D-dimer (g/mL), lactate, pH, troponin, and N-terminal natriuretic peptide (BNP, pg/mL) were acquired. Thrombotic obstruction of the pulmonary arteries was quantified according to Mastora score. The data collected were evaluated by means of descriptive statistics. Spearman’s correlation coeffcient was used to analyze associations between the investigated parameters. P values < 0.05 were taken to indicate statistical significance. Mastora score correlated weakly with lactate level and tended to correlate with D-dimer and BNP levels. No other clinical or serological parameters correlated significantly with clot burden. Thrombotic obstruction of pulmonary vessels did not correlate with clinical severity of PE

A Revised Checklist of Mongolian Mammal Species

A revised annotated checklist of Mongolian mammals is presented, supplemented with comments on modifications in species- and genus-level taxonomy introduced over the last 30 years. The checklist includes 140 species compared to 124 species recognized three decades ago by SOKOLOV & ORLOV (1980). Since then, four species were newly described; seven species were registered for the first time on Mongolian territory. Names for more than 20 taxa have changed, on most occasions this change occurred not for purely nomenclatural reasons but rather as a result of taxonomic revisions at the species level which have elevated the rank of many nominal taxa treated previously as subspecies. Recent molecular studies have shown that many widespread Central Asian species, in fact, consist of several highly divergent phylogenetic lineages the taxonomic status of which is yet unclear. Therefore, further updates to our knowledge of mammal biodiversity in Mongolia are expected

Imaging Findings of Gastric Diverticula

Introduction. Gastric diverticula (GD) are very rare. Computer tomographic findings in GD have been reported only as case reports previously. The aim of this study was to estimate the prevalence of GD on computed tomography (CT) and to analyze their radiological appearances. Materials and Methods. From 2006 to 2013, a total of 14,428 patients were examined by abdominal/thoracic CT at our institution. GD were diagnosed in 18 (0.12%) patients (13 women and 5 men, median age, 64 years). In 9 patients, additional endoscopy and in 7 patients upper gastrointestinal investigation with contrast medium were performed. Magnetic resonance imaging (MRI) was available for 3 cases. Results. In all patients GD were diagnosed incidentally during CT examination. The diverticula were located at the posterior wall of the gastric fundus below the esophagogastric junction. On CT, GD presented as cystic lesions with a thin wall and an air fluid level, located behind the stomach between spleen, adrenal gland, and crus of the left diaphragm. Conclusion. The prevalence of GD encountered in our CT series is 0.12%. GD demonstrate typical CT appearances, namely, cystic lesions located in the left paravertebral region. The radiologist should be familiar with this finding to avoid possible misinterpretations